This invention concerns the application and removal of pressure adhesive sheet layers, such as masking tape used in the manufacture of printed circuit (PC) boards. The manufacture of PC boards currently involves the plating of contacts along one or both sides of the PC board. The contacts are most commonly plated with gold by an electrodeposition process, involving immersion of the side of the PC board in a gold salt bath. The extremely high cost of gold metal as well as a need for a clear border between gold fingers and the rest of the board has led to the use of lengths of masking tape applied to the side surfaces of the board to accurately limit the region immersed in the plating solution. Currently, a pressure adhesive masking tape is employed which is applied manually or by apparatus but which is manually removed after the plating process is complete. The tape must be tightly adherent in order to effectively mask the area of the PC board sought to be isolated from the plating solution, and thus the tape removal process has created a labor intensive step in the process of manufacture of the circuit boards.
Prior attempts have been made to mechanize or automate this process by mechanical stripping of the tape, essentially by vise gripping of the "tail" section and movement of the board by conveyor rollers. Such approach has not been able to be implemented with an acceptable level of reliability.
It is the object of the present invention to provide a process and apparatus which enables a great reduction in the labor involved in this aspect of the PC board manufacture, which process may also be employed in the application and removal of adhesive layers in other contexts.
It is a further object of the present invention to provide such a process and apparatus which reliably and efficiently enables completion of this phase in the manufacture of PC boards.
It is still a further object of the present invention to provide such process and apparatus which does not involve complex and costly equipment and materials to implement.